There needs to be a way to mate iMates together without having to Alt + drag them. When assemblies start to get large, Alt + dragging iMates get very laggy and Inventor takes a huge performance hit. It can become impossible at times to actually mate iMates using this method. Furthermore, there is only two methods of mating iMates: Alt + dragging or using the Use iMates command when placing the component (and a similar performance issue occurs as well).
A new Mate by iMates command needs to be implemented. I developed a custom Add-in myself until Autodesk implements this feature which can be seen the GIF above. The spheres and cylinders you see pop up are from the Add-in and simply act as a placeholders for the iMate glyphs as Autodesk does not have an interface to allow developers to select iMate glyphs. What makes the Add-in so nice is that the user can control the location and size of the spheres and cylinders to their liking and place them on the component that makes sense so that finding the right iMate is easy.
This idea is part of a group of ideas under iMates Overhaul that seeks to improve iMates